vatrace: add IVF header for VP8 coded buffer dump
vatrace: add IVF header for VP8 coded buffer dump

Signed-off-by: Austin Yuan <f447c34e4ebcef84a81b40a8d4dbc448a14e5570@intel.com>

gbeauchesne/libva,gbeauchesne/libva,gbeauchesne/libva